Serum lipoproteins comprise a heterogeneous population of lipid-protein complexes that can be grouped into broad classes, very low (VLDL), low (LDL) and high (HDL) density, based on differences in particle density related to lipid and protein content. VLDL and LDL are composed of predominately lipid, while high density lipoproteins have a higher content of protein (about 50%). The density of LDL is between 1.006-1.063 g/ml while that of HDL and HDL-like particles is 1.063-1.21 g/ml. Classical methods to separate HDL from VLDL and LDL employ sequential density ultracentrifugation using potassium bromide salt solutions prepared with densities in the range of each lipoprotein class. One drawback of these methods for the preparation of purified HDL is that they require a minimum of two prolonged ultracentrifugation steps. The first step, which isolates VLDL and LDL from HDL, requires an 18 hour ultracentrifugation spin in d=1.063 g/ml KBr salt solution. The buoyant VLDL and LDL are concentrated in the upper layers of the salt gradient and can be easily removed leaving the less buoyant HDL along with other heavier proteins concentrated in the bottom layers. The HDL is then separated from other lipid-free serum proteins by performing a second ultracentrifugation step for 21 hours in d=1.21 g/ml KBr salt solution. The HDL is buoyant in this density salt solution thus at the end of the centrifugation, the upper layers of the gradient contains primarily HDL leaving other plasma proteins in the bottom fraction. This sequential density gradient ultracentrifugation procedure is the “gold standard” for isolation of HDL. However the prolonged time required for both ultracentrifugation steps and the need for multiple density adjustments clearly limits the throughput of the procedure.